1. Field
Example embodiments relate to a method for forming a UV-patternable conductive polymer film and a conductive polymer film formed by the method. Other example embodiments relate to a method for forming a UV-patternable conductive polymer film in which vapor-phase polymerization (VPP) may be employed to synthesize a conductive polymer and a UV-curable polymer resin may be used as a binder to form a conductive polymer film capable of being patterned in a relatively simple manner while maintaining increased conductivity, improved transparency and improved flexibility, and a conductive polymer film formed by the method.
2. Description of the Related Art
Recent successful development of digital broadcasting services and increasing demand for high-resolution large-area displays have led to the popularization of flat panel displays, e.g., liquid crystal displays (LCDs) and plasma display panels (PDPs). Digital multimedia broadcasting (DMB) services, e.g., satellite DMB and terrestrial DMB based on the convergence of broadcasting and communications, may be already available, and ubiquitous computing may become feasible. Flexible displays may be next-generation displays capable of replacing existing TFT-LCDs, PDPs and organic ELs.
Such flexible displays require the use of electrode materials that may be transparent, have relatively low resistance and exhibit increased strength so as to be mechanically stable even while being bent or folded. Further, the electrode materials may have improved adhesion to plastic substrate materials and improved chemical resistance to a variety of organic solvents. Furthermore, if the electrode materials are patterned into various shapes while maintaining improved adhesion to plastic substrates, simplification of the manufacturing process and a reduction in the manufacturing cost of flexible displays may be achieved.
Indium tin oxide (ITO) may be used as an electrode material for the fabrication of a variety of display devices, including flexible display devices. However, the use of ITO may result in increased cost and undesirable mechanical properties despite the advantages of improved transparency and increased conductivity on plastic substrates. In addition, etching may be the only method for the formation of circuits using ITO. In recent years, considerable research efforts have been directed toward the development of conductive polymers as electrode materials for flexible displays that exhibit improved characteristics in terms of flexibility, adhesiveness, thermal expansion and printability and that may be in harmony with plastic substrates in terms of physical properties.
Patterning may be a very important technique for the formation of organic electrodes using conductive polymers. A conventional technique for patterning a conductive polymer film for a flexible display device may be carried out by the following procedure. A conductive polymeric material may be coated on a transparent substrate to form a conductive polymer film. For example, the coating may be conducted by spin coating. A photoresist composition may be applied to the conductive polymer film, followed by exposing/etching to form a pattern. However, this photoresist process may be complicated and may use expensive equipment, incurring considerable cost.
Inkjet printing-based patterning may have advantages from the standpoint of ease of processing and cost-effectiveness, but still needs further improvements, for example, in the viscosity and pH adjustment of conductive polymers as ink materials, the development of printing heads and the adhesion of conductive polymers to plastic substrates.